Ammonites are popular shell fossil finds in California
Throughout past geological eras, California terrain went through many changes. Many regions were underwater for long periods of time, and life flourished in those ancient waterways. As lifeforms died, they were covered with sediment, and hard portions of the creatures were preserved. As waterways dried up and became land, these sediments hardened into rock, encasing the remains as fossils. Today you can find a wide variety of shell fossils throughout the state.
Ammonites
Ammonite fossils date back to the Cretaceous Period. They are related to living species such as the chambered nautilus, squid and octopi. Their shells are either coiled or conical and straight. The shells are divided into chambers. These shells range from under 1 inch to 9 feet wide. These fossils are found predominately in North California. The fossils are in large nodules of limestone which can be found embedded in the silt and mud stone outcrops. Good collecting areas can be found along Cottonwood Creek's North Fork and many of it's tributaries. Mill creek, near Red Bluff and Black Rock to the East are also areas these fossils can be found.
Oysters
Fossilized oysters are extremely common in areas of South California. Some areas are littered with them. These are the ancestors of the oysters we love to consume today. Most are the size you would expect from an oyster shell, but they can get quite large. Finding a 6- or 7-inch oyster shell is not common, but it does happen. These fossils occur in mud stone, sandstone and limestone. Good places to hunt for oysters are the Imperial Valley, Yuha Basin and The Colorado Desert. In San Diego county, fossilized oysters can be found in the hills, canyons and beach areas.
Gastropods
Gastropods are commonly known as snails. Some of these are still living today; others have become extinct and exist only in fossil form. The shells of these animals vary widely in shape and ornamentation. Some are coiled and flat. Others are conical, often having whorls and spikes. Snail shells are generally under 1 inch to 3 inches in size. These fossils can be found throughout the shale, sandstones and limestone throughout California. They are often found in deposits listed previously along with other types of shell fossils.
Other Shells
California's mud stone, shale and limestone deposits more often than not will contain fossil remains of many species of shelled animal remains within the same deposit. Clams tusk shells, scallops and even sand dollars are widely found throughout the state. Deposits are sometimes small and localized. Others, such as oyster deposits, are large and cover large areas of ground. Deposits are commonly large enough that layers of specimens can be seen in cliffs. In some areas, such s the Yuha region, fossils litter the ground as well. It is not legal to collect fossils for commercial purposes, but collecting for private purposes is allowed on most public land. If you plan on collecting in a park area, you need to check regulations at the office before collecting.
Tags: fossils found, These fossils, found throughout, oyster shell, shell fossils, Shells California
